Machine tool feed



l May 26,1953 F. M. .'r'oMLlNs'N 42,639,736

MACHINE TOOL FEED Filed Sept. 30, 194'? 3 Sheets-Sheet 1 F. M. TOMLINSONMay 26, 1953 MACHINE TOOL FEED Filed Sept. 30, 1947 3 Sheets-Sheet 2 MmmINVENTOR.

F M.T uN n n] nMLlNs .l

May 26, 1953 F. M. 'roMLlNsoN MACHINE TooL FEED Filed sept) 3o, 1947 ssheets-sheet s INVENTOR. MTJMLINSEN FITTDR'NE Patented May 26, 1953MACHINE 'rooL FEED Fay M. Tomlinson, Lakewood, Ohio, assignor to TheWarner & Swasey Company, Cleveland,

Ohio, a corporation o'f Ohio Application September 30, 1947, Serial No.777,031

12 Claims.

This invention relates to a machine tool feed and, more particularly, toan improved fluid pressure actuated means for operating the chuck andbar feed mechanism of a bar type machine tool.

An object of the invention is to provide a novel and improved fluidpressure operated mechanism for actuating the work-holding chuck and thebar feeding mechanism of a bar type machine tool under the control of asingle valve.

Another object of the invention is to provide a novel and improved fluidpressure operated mechanism for actuating the bar feeding mechanism of abar type machine tool to feed predetermined lengths of the bar stockwithout requiring the use of a stock stop.

Another object of the invention is to provide a novel yand improvedfluid pressure operated mechanism for actuating the chuck and barfeeding mechanism of a bar type machine -tool under the control of asingle manually operated valve,` the improved mechanism being soconstructed and arranged that operation of the said valve to oneposition automatically sequentiallyv actuates the chuck to work-grippingposition and prepares the bar feeding mechanism to feed a predeterminedlength of bar stock, and operationl of said valve to another positionautomatically sequentially actuates the chuck to Work-releasing positionand feeds the predetermined lengt/h" of the bar stock.

A further object of the invention is to provide an apparatus of the typedefined in the preceding object with means to brake the movement of thebar feeding mechanism adjacent its forward position in a bar feedingdirectionthereby reducing the force with which the feeding movement ofthe bar stock terminates. y

A still further object of the invention is to provide an apparatus ofthe type dened in the two preceding objects with a novel means foradjusting the length of feed of the bar stock without. altering theoperation of the fluid pressure actuated mechanism. I

An additional object of the invention is to provide a novel and improvedfluid pressure operfeeding .mechanisms of a bar type machnetool, whichmechanism comprises a fluid pressure actuated piston for operating thechuck to and from gripping position, and for controlling the actua-4.

ated mechanism for actuatnig the' chuck and bary (Cl. L10-130.2)

2 uned in Ame preceding object and wherein the' fluid pressure operatedmechanism for actuating the chuck and bar stock feeding mechanisms,l

comprises a compact unit readily attachable to existing bar typemachines.

A still further object of the invention is to provide -a novel andimproved fluid pressure operated mechanism for actuating the chuck andbar feeding mechanism of a bar type machine tool under the'control of asingle manually operated valve, the said valve being so constructed andarranged that it automatically returns to neutral position, means beingprovided to delay the return of the valve to neutral position afterbeing l,operated for actuating the chuck to Work grip-l ping positionthereby insuring that suicient uid pressure is appliedto said chuckoperating mechanism for proper operation thereof.

AAn additional object of the invention is the provision of a novel andimproved means for indicating the fluid pressure employed to effectwork-gripping by the jaws of the chuck of a machine tool, whichApressure is proportional to the pressure exerted upon the work by thejaws ofthe chuck, the said means including a device to preventlindication of surges in the fluid pressure which are disproportional tothe jaw pressure.

A stillfurther object of the invention is to provide" a novel means forinterconnecting the actuatingjlever of a chuck with a member moving in astraight line, which means is so constructed and arranged that thelatter member moves the actuating lever with substantially no radialthrust so that lsubstantially the entire force of said member iseffective to produce actuation of the chuck. i

The invention further resides in certain novel features of constructionand combinations and arrangements of parts, and further objects andadvantages thereof will be apparent to those skilled in the art to whichit pertains fromthe following description of the present preferredembodiment thereof, described with reference to the accompanyingdrawings, in which similar refefrence characters represent correspondingparts throughout the v'several views and in which:

Fig. lI is a fragmentary front elevational view of a bar type machinetool provided with thenew and improved fluid pressure yoperatedmechanismrfor actuating the chuck and the bar 'feeding mechanism of theytool;

Fig. 2 is an enlarged fragmentary view, partly in section and partly inelevation, illustrating the headstock *of ythe machine tool and the' newand impofvedjmechanism of the 'invention as' appliedv to the machine,the view being taken from the rear of Fig. l with the cover for thechuck actuating mechanism removed;

Fig. 3 is a fragmentary sectional view of the actuating mechanism formoving the bar stock feeding chuck, the view being taken substantiallyon the section line `3-3 of Fig: 2f;

Fig. 4 is' an enlarged view of the riglut-handy portion of Fig. 3;

Fig. 5 is an enlarged sectional View of the; surge prevention device forthe chucking Apres:

sure indicator which is mounted upon theAhead-e Fig. 5a is a furtherenlarged fragmentarysecfj tional View of a .portion of the surgeprevention device illustrated inFigs. 2 and 5; f i A Fig. 6 is anenlarged sectional view ofethe novel fluid pressure actuated Vunitillustrated to a smallerscale. in Fig. 2, for .operating the chuck andbar stock feeding mechanisms rig'. .7. is an enlarged seouonai viewoftiie n ove1 manually operated valve for' the improved mechanism,illustrated to a smaller Scale in FiaZ;

Fig. 8 is an enlargedview, sectinnand A ing! the actuating.mechanisrnofthe latt'eerA ,y The,

rods I2 and ,i3 .are supported. in.a.convetional mannerby a bracket.member1|4 mounted upon the-upper end of a vertical standard. |5,,latera1 supporti. being. provided ,by a. substantially. horifj. zontalarm .ill extending betweenthe base ji l a n d the-bracket memebr Ul,.The.rodleiitendsbee yond thelbracket I.-.andis additi nally suppe; edbyvone crmorevertic-al stand .such-as l '1, one or :morehorizontallyeg'it'ending'.bra "g`.,ro d s or.ba`rs i8 beingL connected betweentlrlvertical standards to prov-ide a rigidstructure. g .Theu'ppeij end ofthestandardl 'i is provided with y apivoted sleeve. Ilaforrslidablysupporting .n.bargstock- `tube I9 which.is.also..supported upon theuppersurface oi. the bracket .ILf/f-Ihfat.- end of the bar stock guiding tubeI9 adjacentithle headstock-Ii .has abarfeeding chuck-. generallydesignated 29,. mounted thereon.. The lower por,- tionof l 4this`feeding chuck is provided.. with. suitable-bores' through whichwtherodsl andi; pass with -asliding.t to .additionally support andguidethefeedngchuck. 1 if., Thev .bar` feeding chuck. 28 -isadapted.,to. feed a, predetermined length.df .bar stock 2I tlirru'ighVa..conventional .work-holding. chuck 22e, which may beofthe collet type,carried the,.ho ll ow work. spindle .23 rotatably mounted. in theheadstock, l. of-.the.machihe. tool.,...f'l,`l'1 e` spindlela isprovided with (zonventnal ineens),for;l effecting rotation thereof and.the, collet .chuck 22 is of the type employing spring jaws -'D'Clt'ed in'thewellr known manner by .an actuating sleeve M .,Whh extends -throughthe spindle 23 ,as is .well known initieert. ,Movement of theactuatmgiseiected bymeanfsof chuckactuating bly 25 mounted il'p th ea d f therThis chuck actuating assembly comprises the usual housing 2S in which aplurality of chuck actuating ngers 21 are pivotally mounted. As iswell-known in the art, these ngers are in the form of levers, theshorter arms of which engage the chuck actuating sleeve 2li to move thelatter andfhence thefspring jawso the -collet chuck towork-(grippingpositioniwhen the longer arms of the fingers are movedoutwardly.

'E'his outward movement of the longer arms of the fingers 21 is effectedby an actuatingcone 2-8 `which -is slidably mounted on the spindle 23and hasaninclinedsurface for engaging rollers if, f'faonsnthe' ou-ter`ends of the longer ends of the y lingers-.Zlcithe cone` also having theusual land portionvon V\v l 1ich the rollers 29 rest when the oliuckin-work-gripping position. The cone f' 28 isiurtherI provided with theusual groove til in which rollers 3i, provided on the ends of the upper.bifurcated portion 32a of anactuating lever onyoke 3Z', are positioned.This lever or yoke', is, flc atably mounted. by being pivoted intermediate its.endstQtheouter ends of a pair of spaced` links; 33 whichstrad'dle the lever or yoke aridhave th'eirinnerends' pivotedto anintegral' boss orbracket 35j provided uponthe rear o fLthe' heads'tockj'! The lower. portion or arm 32h of thelever'32 is alsolbifuncated andis pivf otally 4connec ted to one end of a link 35, the other en .o`jf,which.is` pivoted-t ja bossjor bracket 35a ed upon the rear.ofthexheadstock. r"ihe ortion 321? ofthe .lever 32 is .also pivotallyconn c'te'd to-the outer yend of a. piston rod, of a ilu'id 'pressure'operated. mechanism, generally designated 35, forming a par't of 'thisvinvention and .which Will be hereinafter described in detail.

From ,the 'truc'tion just described, it will be readily apparent thatwhen the .lower end of the ami or portion' ,3215. ofthe leven 32 ismoved to the left, .as seen in Fig'. 2,.the arm or portion 32a thereof.will move' the cone 28 to the right thereby rockingthengers 2l whichcauses the collet chuck 4tog'rpy thefwork. Movement of the lower' end ofthe leverfor.yoke portion, 32h in the opposite,. .direction,moves ,thecone 28 to the left, as

viewed inl 2, thus, enabling the rollers 29 of thengersl to move,inwardly under the force providedby thereSiliency of the. spring jaws ofthe collet chu-ck, thereby rs'e'leasingy the work gripped4 therein.,Thepivotal mounting of the lever .3 2 by-meansof .the links 33 and 35enables thelower end. of thelev'er to move in substantially astraightlinewhen, actuatedY byv the fluid pressureoperated mechanisms@Hence, the entire thrs'tof the mechanism 36is effectivev in moving thelcone 28l and there .is no appreciableV radial thrust.. upon the v leveror'.` its pivotal mountings. The chuckactuating assembly 25 and the cone28 fpractuatingthe. chuck are normally enclosed within a conventionalcover 3l to prevent entrance of .dirt.into .the moving part thereof.

The bar stock 2l extends through the collet actuating sleeve,.24 andthrough the chuck 22 housing member, generally designated 38, which isslidably supported on, and guided by, the rods I2 and I3. The upperportion of the housing 38 is provided with a central bore in which aremounted anti-friction bearings 39 for journalling a reduced diametersleeve portion 40 of a rotatable member 4| which has a central bore ofsufficient diameter to freely receive bar stock of the greatest diameterto be employed in the machine and without contact between the bar stockand the wall of the bore. The member 4I supports the jaw assembly of thebar stock feeding chuck, which assembly comprises a scroll 42, see Fig.8, rotatably retained on the forward face of the member 4I by an annulargroove in the inner face of an integral cylindrical jaw supportingmember 43. The latter is supported on the member 4| by a slightlyreduced diameter portion thereof and by a ring member 44, the innersurface of which is substantially coextensive with the bore in themember 4I. The jaw supporting member 43 is provided with radiallyextending T-shaped recesses or slots in each of which a jaw member 45 isslidably positioned, see Fig. 8a. Each jaw member is provided with alongitudinally extending opening in which is positioned a movable plug4S, the outer end of each of these openings being closed by a coverplate 41. The plug members 46 are each provided with a longitudinal borein which is positioned a compression spring 48, the ends of the severalsprings projecting beyond the plug members and engaging the said jawmembers 45 to urge the latter in bar stock engaging direction.

'I'he outer face of the scroll 42 is provided with a spirally arrangedthread cooperating with segmental threads upon the inner faces of theplugs or members 46 to radially move the latter, thereby adjusting thecompression :of the springs 48 and` hence the pressure with which thejaws 45 grip the bar stock, when the scroll is rotated. T permitrotation of the scroll for this purpose, its inner face is provided withbevel gear teeth 42a which mesh with a bevel pinion P having an integralcylindrical portion journalled in an opening in the jaw supportingmemberv 43 and provided with a polygonally shaped recess R for thereception of a suitable tool.

The construction is such that, by inserting a suitable tool in therecess R, the pinion P may be rotated thereby thus rotating the scroll42 so that the spiral thread thereon, cooperating with the segmentalthreads on the members 46, cause the latter to move radially. Thisadjusts the compression of the springs 48 and hence the force with whichthe jaws 45 engage the bar stock 2 I. The plug members 45 are adjustedto an extent to cause the jaws to rmly grip the bar stock 2| withsufficient force so that the latter is moved through the chuck actuatingsleeve 24 and the collet chuck 22 when the feeding chuck 20 is moved tothe left, as viewed in Figs. 2 and 8, by means of the novel fluidpressure operated mechanism hereinafter described. When the bar feedingchuck is moved in the reverse direction and the forward portion `of thebar stock is still held by the chuck 22, the jaws 45 yield radiallysuficiently to allow the chuck 20 to slide or be stripped along the barstock 2| to a new position.

The housing 3B for the bar feeding chuck 29 is also provided with abranch arm 49. The upper end of this branch arm 49 is provided with anopening to receive the guide sleeve lor tube I9 and a clamp member 59,adapted to beactuated by a screw I, is provided to effect clampingof thearm to the tube I9. Hence, when the bar stock 2| is fed forwardlythrough the collet chuck of the machine tool the bar supporting tube orsleeve I9 is carried therewith. However, when the bar stock feedingchuck 29 is moved rearwardly, while the collet chuck is in engagementwith the work, the said bar stock feeding chuck and sleeve I9 movetogether rearwardly of the machine so that there is relative movement atthat time between the bar stock 2| and its guiding sleeve I9 as is wellunderstood in the art.

In accordance with this invention, fluid pressure actuated means areprovided for operating the collet chuck and bar feeding mechanisms inpredetermined sequence and under the control of a single main valve. Inthe illustrated embodiment oil is employed as the fluid which issupplied under pressure for actuating the novel mechanism. However,other liquids may be employed or a gas such as air may be utilized andhence the term uid in the description and claims is intended to beconstrued generically.

In the form of the apparatus illustrated in the drawings, the bed of themachine tool is provided with a sump or reservoir 52 below the headstockI0, which reservoir is adapted to contain a suitable uid, preferably oilor' the like. Fluid is removed from the reservoir 52 and is supplied tothe actuating mechanism by means of Ia conventional pump 53 which isdriven by a mechanism, not shown, the pump being connected with anintake pipe 54, disposed within the reservoir, with its lowerl endextending adjacent the bottom of the latter. The output of the pump 53flows through al pipe or conduit 55 which communicates with an arcuaterecess 56 in a rotatable valve body 51 of a multiple passageway mainvalve, generally designated 58, the portion or body 51 of the .valvebeing mounted for limited rotation in a casing 59 which has a bore orpassageway 69 therein connected with the previously mentioned conduit orpipe 55. The construction is such that the bore or passageway 60 is incontinuous communication with the recess 56 of the rotatable portion 51of the valve for `all positions of the latter.

The housing or casing 59 of the valve is also provided with twosubstantially parallel bores or passageways 6| and 62 which are adaptedto be selectively placed in communication with passageways 63 and 94,respectively, in the rotatable portion 51 of the valve or with a recessportion 65 provided in the rotatable portion 51 -of the valveintermediate the passageways 63 and 64. The rotatable portion 51 of thevalve is preferably cylindrical and the recess 65 thereinextendssubstantially parallel with the axis of the valve, this recessbeing in communication with a bore 66 and an exhaust passageway 61provided inthe housing 59 o-f the valve. The bore or passageway 61 isconnected by a tube or conduit 68 with the reservoir 52 therebyproviding an exhaust or return for the fluid. The rotatable valve body51 is ialso provided with a radial bore or passage- `way 59 extendingfrom the recess 5 6 and communicating with the passageways B3 and 64,The passageway 69 is likewise in communication with a radially extendingbore or passageway 10 in the valve body 51, this latter passageway beingadapted toI be selectively placed in communication with a bore' orpassageway 1I through the wall of the valve housing 59.

The passageway 62 inthe valve body 59 is connected with one end of-apipe or conduit 12 4the other l. end of -whichcommunicates withinterspear-sa cnecreepises'or conduits-1a., 1r indus-- (se-ef Figlio-llY 'I'liepipe-or conduit 'i3 is in communication `withthefinteriorfof vacylinder '76- through ai port TI, in thesidev wall `of theVcylindervadjacent one-end. This cylinder comprises a part ofthe actuatingmechanism 36 for operating the collet chuck` and the bar feedingmechanism` and is'provided'with an elongated piston 18" the length'ofwhich is proportional to the longitudinal movement of the collect chuckactuating cone 28. The piston 'i8 is provided witha piston rod 'J9 whichisl pivotally connected to the lower end ofl thekb'ifurcated'portionl orarm 32h of the c 'huck"` actuating lever 32, as previously described.The cylinder 'i6' isalso provided with a port 80 adjacent the endopposite tofthat provided with' the port/'I1 and intermediate itsendsthe cylinder isprovided with a third port 8|. The length of thepiston' '|8is such that when in either extreme position it will uncoverthe port 3| but will close this port relatively soon after being movedfrom that extreme position. v

The cylinder 'iS is preferably formed as a part ofa unitary housing32'for the actuating mechanisrn although it will be understood that theSeveral parts of the latter` may be formed seperately and interconnectedto provide a unitary device. This housing 82'has Aan openingtherethroughA above the cylinder 'It 4for the receptionofseveralconduits or pipes such as l2, i3, lli, etc. Above this openingthe housing 82 has a horizontally extending cylindrical bore 83 in whichis' provided a cylindrical valve member 8l! comprising spaced lands 85',86, 8l and 88 which have a Sliding, substantially liquid-tight, iitwithin the' bore`n83'. The portions of the valve between the lands areof reduced diameter, as is clearly shown in Fig. 6, and the ends of thevalve have projecting portions to limit its movement within the bore S3.The housing E2 is also provided with a plurality of ports 39', Bil, 9|,92 and 93 communicating with the bore 33 the open end ci which is'closed by a plug 94 to provide a iiuidtight closure'.

Above the bore 83 the housing 82 of the fluid pressure actuatedmechanism 36 is provided withl a bore or passageway 95 one end of whichcommunicates with the bore 83 adjacent the central portion thereof andon the opposite side of bore from that in which the ports 89 to 9,3 arelocated. The other end of the passageway 95 communi- Cates with the endoi a cylindrical bore 96 in the upper'portio-n of the housing 82, thisbore 9B constituting -a cylinder for the bar feeding actuating piston.rihe ends of the bore 96 are closed by a plug Sil and a stuffing glandand nut 98, respectively. A piston rod 99 passes through the stuffinggland and nut S3 and its inner end is provided with a piston |03. Thebore 96 is provided with a radially extending port |I Iadjacent to, butspaced from, the plug 91 and this port communicates with a passageway|02 which extends into communication with the bore or cylinder 83adjacent the central portion of the latter on the opposite side of thebore 83 from that in which the ports 89| to 53 are located. Closelyadjacent the plug'l the cylinder or bore 96 is provided with anotherradially extending port |63 which also communicates at certain timeswith the passageway |32, the outer end of the passageway |02 beingcounterbored and provided with a spring pressed ball valve |04 held inplace by a plug l which also serves to sealthe end of 'the passageway|02; The construction is such 'thatthe port |03 is in communication withthe passagesl way`Vr |A 0 zonly when thefball valve: |04' is'unseatediagainst the force.v of its` spring: Intermediate. the;-v portsl Iiland|03 the wall ofthe cylinderA 9S provided withatapered recessv 06, seealso Fig. 3;

f' for a purpose hereinafter described.

Thef piston rod'99 extends through a borein a biacket'member- |01, therod being connected to themember by a, dowel pin Hi8; The portion of thepiston rod beyond'this' bracket member-is' designated H0 and'v extendsto and through a recessed opening in the bottom ofthe housingv 381 forthe bar stock feeding chuck 20'. While the portion of the piston rod'hasbeen illustrated as formed integral withthe portion 99 it will beapparent thatthese maybe made separate and coupled together byconventional means. This would facilitate assembly ofthe parts and*compensate for small mis-alignments between the various` openingsthrough which the rod passes.

The' lower portion ofthe housing 330i the bar stock' feeding chuck isprovided with a transversely extending screw H2 the inner endA of whichis adapted to engage the side cf the portion Hi) of the piston rod" 95,see Fig. 4. The other side wall ofthe recessl in the lower end of thehousing 38 is provided'l with a screw H3 the axis of' which extends atan angle with respect to that of the screw l I2. Between the inner endof the screw ||3` and the rod there is provided a roller llt which has acentral opening in which a pin` is disposed. The pin is carried by thehousing 38' and is considerably smaller in diameter than the opening inthe roller. The. housing 38 is also provided with a, compression springwhich extends at substantially right angles to the screw H2 and bearsagainst the periphery of the roller IM. The angle of inclination ofthescrew H3- relative to the screw H2 is such that the roller Hd acts as aball or roller clutch for gripping the portion I lilv of the piston rodwhen the bar chuck 25B is moved to the left as viewed in Figs. 2 and 3,that is, in Aa direction for feeding bar stock to the machine. When therod is moved in the reverse direction the roller li can shift slightlyagainst the spring Ei so that the portion Il@ of the rod can now slidefreely through the housing 38 of the mechanism 2li.

Release of this roller clutch at any time is readily effected by meansof a manually operated lever i5 pivotally attached adjacent the bottomof the housing 38 by connection with a vertically extending camming rodIl? which is journalled in the housing 38. This rod H'l extends adjacentthe roller I4 and has a flattened or recessed portion on one sidethereof. Hence, by turning the handle or lever |6 the rod i Ii isrotated from the position shown in Fig. 4, moving the flattened orrecessed portion away from the roller H4, so that the rod ||1 shifts theroller Ill against the action of the spring H5 thereby disengaging theroller ||4 from contact with the portion i0 of the piston rod so thatthe bar chuck 2@ may be freely moved with respect thereto. In order toretain the rod IH and lever Ht in their positions illustrated in Fig. aa spring H8 is provided, which spring extends about the rod ||1 and hasone end connected with the housing 38 and the other end connected withthe manually operated lever 6 by a pin or the like.

Movement of the piston rod 99 rearwardly of the headstock Ill, that is,to the right as shown in Figs. 2 and 3, is limited by means of athreaded shaft or screw I9 which has one end screwed within a projectinglug on the bracket member It?, the other end of the threaded shaftextend- 9 ing with a sliding t through and beyond' a projecting lug |I|on the body of the mechanism 36 which is, in turn, iixedly secured tothe rods I2 and I3 or directly to the headstock of the machine. Thethreaded shaft or screw ||9is provided with adjusting nuts |20 toregulate the amount of relative movement between the member |61 and thelug I|| on the housing for the mechanism 36. The construction is suchthat when the piston rod 99 is moved rearwardly with respect to theheadstock, to the right as shown in Figs. 2 and 3, the bar chuck 20remains stationary, the portion of the rod slipping with respect theretoby the action of the roller |4. The extent of this rearward motion isdetermined by the positions of the nuts |20 upon the threaded shaft ||9,the movement of the portion ||8 of the piston rod, relative to the barstock feeding chuck, in this direction being terminated by the nuts |20abutting the lug I I I. It will be remembered that the bar stock chuck20 grips the bar stock 2| and that when the piston rod moves to theleft, as viewed in Figs. 2 and 3, the portion I I0 thereof is gripped bythe roller |I4 and screw ||2 so that the bar chuck is moved therewith.Therefore, movement of the piston rod 99 to the left feeds the bar stock2| through the collet chuck 22 of the machine tool, so that theadjustment of the nuts |20 upon the shaft or screw H9 determines thelength of bar stock which is fed during each movement of the bar stockfeeding chuck 20. The feeding of the bar stock occurs sequentially withrespect to the actuation of the collet chuck by virtue of the operationof the piston 18 and the valve member 84 in the actuat..`

ing mechanism 36 as hereinafter described.

The fluid connections to the cylinders 16 and 63 of the actuatingmechanism 36 are completed by pipes or conduits |2|, |22, |23, |24 and|25.

Thus, the pipe or conduit I2| has one end con-- nected with the bore 6|in the casing for the valve 58 while the other end of this pipe orconduit is connected to pipes |22 and |23 which are, respectively,connected tothe port 80 and to the port 89, see Fig. 6. The conduit orpipe |23 is also connected by the pipe or conduit |24 to the port 92,and the ports 8| and 9| are connected by a pipe or conduit |25. Themechanism 36 is, therefore, connected with the valve 58 in a manner suchthat the operation of the device is effected by selectively positioningthe valve body 51 of the valve to establish communication betweenvarious of the passageways therein and the pipes connected with thecylinders of the mechanism. Positioning of the valve body 51 is effectedby means of a manually operated handle or lever |26 connected with thevalve body and rockably mounted upon the headstock |0 of the machinetool Where it is conveniently accessible to the operator who effectsfeeding of the bar stock and chucking thereof by selectivelyv actuatingthe said handle |26 in opposite directions, the rotation of the valvebody 51 in either direction being limited by conventional stop means,not shown.

In order to facilitate understanding of the mode of operation of theapparatus described above, let it be assumed that a machining operationhas just been completed so that it is rst necessary to release thecollet chuck and to feed a new length of bar stock through the chuck,and then to againr grip the bar stock by means of the chuck and preparethe feeding mechanism for its next operation. I'he operator begins thiscycle of operations by grasping the handle |26 vand rotating it in thedirection which brings the pas- 10 sageway 63 of the valve body 51 intoalignment with the port 6|. Since the pump 53 is in continuous operationduring the use of the machine, oil or other suitable fluid is withdrawnfrom the reservoir 52 through the pipe 54 by action of the pump, theliquid being forced upwardly through the pipe 55 and into the recess 56of the valve body. From the recess 56 the uid under pressure flowsthrough the passageways 69 and 63, to and through the port 6|, andthence through the pipes |2| and |22 into the cylinder 16 adjacent theleft hand end thereof as viewed in Figs. 2 and 6. The fluid underpressure thus admitted to the cylinder 16 by operation of the valve 58forces the piston 18 to the right as viewed in Figs. 2 and 6. Hence, thepiston rod 19 rocks the lever 32 moving the finger actuating cone 28 ofthe collet chuck mechanism to the left as viewed in Figs. 2 and 6thereby releasing the lingers 21 so that the jaws of the collet chuckmove, by their natural resiliency, to work releasing position. Any fluidin advance of the piston 18 is exhausted through the port 11 and pipes13, 12 which are now in communication with the drain or exhaust recess65 in the valve body 51, it being remembered that the recess 65 is incommunication with the reseris/oir 52 through the passageways 66, 61 andpipe At the same time that the fluid under pressure was applied throughpipes or conduits |2I and I 22 to the cylinder 16, uid under pressurewas also applied through the pipes |23 and |24 to the cylinder or bore83 through the ports 89 and 92, respectively. This pressure acts uponthe land or piston portion 85, of the valve member 84 to exert forcethereon so that the valve member 84 moves to its extreme right-handposition as shown in Figs. 2 and 6, any fluid in advance of the land orpiston portion 88 being exhausted through port 93 and pipes 15, 12communicating with the exhaust recess 65 in the valve body. The actionof the fluid pressure upon the land or piston portion 81 does notinterfere with thisl operation since it is balanced by the action uponthe land or piston portion 88.

As the piston 18 nears the end of its stroke, which, as mentioned above,effects release of the collet chuck, it uncovers the port 8| in thecylinder 16. Hence, fluid under pressure now flows through the cylinder16 from the port 80 to and through the port 8| and thence through thepipe |25 to enter the cylinder 83 through the port 9|. The valve member84 having been moved to the right, as mentioned before, a. passage isprovided between the lands 86 and 81 to the passageway 95, thepassageway |02 having been sealed off from the port 9| by the land 86.The pressured fluid therefore passes through the passageway 95 andenters the cylinder 96 adjacent the righthand end thereof causing thepiston |00 to move to the left as viewed in Figs. 2 and 6.

The movement of the piston |00 to the left as viewed in Figs. 2 and 6,causes the piston rod 99 to be moved to the left. As the portion ||0 ofthis rod is thus moved it carries with it the bar stock feeding chuck 20since the ball or roller type clutch, provided by the roller ||4 and theassociated mechanism in the lower portion of the housing for the barstock feeding chuck, firmly grips the rod. Movement of the bar stockfeeding chuck 20 in this direction causes the bar stock 2| to becorrespondingly moved or fed since the Jaws 45 of the bar stock feedingchuck grip the bar stock. In order to slow up the feeding movement ofthe bar stock when it nears the end of its 1.the exhaust recessV 65.therefore, supplied from the conduit 55 and recess movementhoveibre'kiiigacuon'is provided for the barfeedingmechanism. Thisbraking action i's1d1eto'the`provision of the spaced ports |IJ|, -ir'and the taperedgroojve or recess I 'adjacent the left-hand end ofthercylinder E6. As the port' of the valve 5S which is now incommunicationwith thev exhaust recess 65. As the; piston lil!)approaches the end of the cylinder 36 the `port UJI Lis closed bythepistonexcept forthe openingthereto provided by thetapered recess |06. Asthe piston continues to move further' t'owards the plug 9'! the huidinadvan'ce of the fpiston must nov/'now through the restricted ori-.,ficeprovided bythe tapered groove or recess |95 communicating withpassageway |82, this tapered :groove or recess being'disposed So thataprogressively smaller area is available for exhausting ythe uuid asthe'piston .approaches the end of the cylinder. Hence, a dashpot or brakingaction is effected so that the bar stock, fed by movement .Tof thepiston ffii?, comes torrest without eliecting any appreciable blow orimpact due to the abutment of the vbracket member I B'I with the nut 98of the' housing St. As is well-known inthe art, a fixed stock stop (notshown) may be provided upon the machine' tool' against which the forward1 portion of the bar stock abuts to limit the length thereof extendingbeyond the forward portion of l. the collet chuck. 'When such a stopkisemployed the above-mentioned brakingordas'hpot action is additionailyadvantageous since Vit prevents the' bar stock from striking the stopwith sufficient .force to cause springing of the parts o1' rebound ofthebar stock.

A,The 'operator now 'grasps the handle |28 and moves the latter in theopposite direction to the previous'actuation thereof, thereby rmovingthey,valve body'5'l to place the passageway |54in alignyment with the portor passageway 62 and the port or passageway -tl in communication withFluid under pressure is,

56 through the passages 69 and S4 of the valve, ,andthis iiuid passesthrough the port or vpassageway. 62 and'conduits 12, 'I3 toenter thecylinder 75 through'the' port 'l1 thus forcing the piston 78 to the leftto its position as shownin Fig. 6., This causes the piston rod 'I9 torock vthe cone actuating lever 32 in a direction to -move the4 fingeractuating cone '28 to the right as shown in Fig. 2 thereby rocking 'thengers 21 in the direction which effects closing or work- Lgripping ofthe jaws of the collet chuck so that the newly fed bar Vstock is rmlygripped.

Fluid underpressure is also simultaneously admitted through the conduit75 and port 93 to the valve cylinderor bore 83,`and through the .pipe.le to the valve'cylinder or bore 83 through .the port $0. `Thepressureexertedby the duid entering the port. 93 is effective upon the landorpiston portion 88 to move the valve body' `84 to theposition as shownin Fig. 6 while the pres- ,sure exerted upon the lands or piston,portions f85fand 86 by the fluid admitted through the .port`lllllbalance 'each other. This movement of "the rv'alve body '8A nowyprovides a communicating p'a'th through Ithe cylinder '8'3 "between theflands' '86 'and`8'1'so that uid -under fpre'ssureicaninow `f|ow"fromthe cylinder "16 "through the iprt 73|,

which was uncovered by'movementfof 'th'episton '|8'to itspositionfa-s'sho'wn"inFig 6. The'uid therefore passes throughithef'port'8| and pipe 'i2 5, hows -between the -lands "86, *31, and thence-through 'the passageway `|02 Ithereby unseatin'g the ball 'valve |04,'so vth'afth'e fluid 'under press'ure "enters 'the 'cylinder'-f9`6through the port i113. This id actsju'poh"thepistonfl06 4toimove thelatter tothe right Tan'dto `its "p'ositidnsubstanti'ally' 'as 'shownin'- Fig: 6 during which 'move- Ynientthe port {Oli-iis alsouncoveredlproviding r4an" additional pat-h `for -`the pressured huid.

During v'this' movement "of the piston we -t'he Huidintheright-handportion of the cylinder @E is exhausted through 4thepassageway "95, through the `passage in the 'cylinder '83 providedbetween the lands 81 and 8`8"a'nd `through`the portQZ vto the pipe |24.'From thence thefexfha'ustefd fluid passes 'through 'pipes |22'1arid'i2lvinto the port orpa'ssagewayl of the valve"58,

through the recess'65 and 'passageway 8E v'to the return conduit B7, andthence 'downwardly through 'conduit'fsgto "the reservoir vv52, The"iiuid 'adjacent thefleft-ha'nd 'side' o f the vpiston l2 V and throughthevalve lpassagev'vaysiandfpi'pe 58 "to the reservoir.

j mechanism' 36. This liIfnitsthemovement of the viniston 'll due tothefactthat its y`rod 59' is Vconnected with the 'shaft or screw I I9 bythebracket |07. During 'thisv movement 'of the piston |00 The impr'ovedniech'autism of this invention is alsoprovided v" vv'fith iiiea'ns'` forautomatically returning 4the'valve"hdy''51"of'the yvalve 58, and hencethe handle |26, to neutral positionwhen the saidhandle'isreleas'ed bytheoperator.` This position for the 1valveiit is that'fillustrated in Figs.2 and 7 from'which'it `Willibe` sen'that the `fiiiid under pressure'`'suppliedtliibughthe conduit 55 now'fenters the recess 56 andpassageway A69 'flowing through the pass-agewaysfl' "and 1| "to a pipeorv conduit T2?. This 'pipe leads to a conventional' lubrica'tingvreservoir not lshown) 'in the hea-'estuchar the machine, sincethe fluidemployed in'theillustratedjeinbodiment is oil, the excess iiuid from theIlatter- /being' f r'et'ur'ne'd vare "both r'in communieation the recess:65

fin the valve body 51,"which" recess Icor'nniuniea'tes with the"r`eturnor "exhaust Apipe 't8 5 'throughthe passageways 66 and''l off the'valve. Hence," ary num pressures within' the cylinders `Xis; 831-and 96are'released' so thatno partof theactuating mechanism" 36 remainsunderpressure.

In order to Lautomatically'returri thek valve'bdy 51 andhandle- |26 totheir/neutral positions'fas shown in Figs. 2 and 7, the said body isprovided with a radially extending projection |28 which has asubstantially cylindrically shaped outer portion received betweenplungers |29 and |30. These plungers are slidably positioned in bores inthe body 59 of -the valve, which bores extend at right angles to theplane of the member 28 when the latter is in neutral position. Theplungers |29 and |39 are resiliently urged against the member |28 bycompression springs |3| andv |32, respectively, the outer ends of whichrespectively bear against the bottom of the bore for the plungers and aplug |33 which closes the bore.

The springs |3| and |32 are of equal strength and, hence, act to returnthe valve to its neutral position as soon as the handle |26 thereof isreleased. However, in order to insure that sufficient fluid pressure hasbeen applied to the fluid operated mechanism 36 to eiect complete workgripping action of the collet chuck, means are provided to delay thereturn of the valve body 51 to its neutral position for a predeterminedlenth of time after it is actuated to chuck closing position. Thisiseifected in the present construction by providing a notch or recess|34 in a portion of the periphery of the valve body 51 for cooperationwith a spring pressed, ball type detent 35 mounted in the housing 59 forthe valve and acting radially inwardly. Hence, when the handle |26 ofthe valve is moved in a direction to effect work gripping by the colletchuck, the recess |34 of the valve body 51 moves into alignment with theball detent |35 and the latter exerts sufficient force to hold the valvebody in its operated position against the action of the spring |3| whichnormally tends to return the valve to its neutral position.

The passageway 64 of the valve is now in communication with the port orpassageway 62 so that fluid under pressure also flows through a branchport or passageway |36 communicating with the port or passageway 62.This passageway |36 is provided with an adjustable needle valve |31 toregulate the rate of passage of the uid therethrough and through theconnecting passageway |38. The passageway or port |33 is connected by apipe or conduit |39 with a passageway |40 in the valve body 59 and thislatter passageway also communicates with the bore in which the plunger|29 is positioned so that the fluid under pressure is applied behind thelatter. The passageway |40, in the neutral position of the valve,communicates with a recess |4| in the valve body 51, and this recess isconnected by a passageway |42 with the exhaust port or passageway 61.However, when the valve is :actuated to chuck closing position, thepassageway |40 is no longer in communication with the recess |4I. videdwith a port |43 which communicates with a cylinder |44 provided in thevalve body 59. Within the cylinder |44 is slidably positioned a piston|45 having reduced axially extending projections |46 and |41 forengaging the end walls of the cylinder and thereby preventing the pistonfrom sealing the port |43, and the port |48, the latter being providedin the opposite end of the cylinder from that in which port |43 ispositioned. The port |48 is connected by a conduit or pipe |49 with thepipe |21 leading to the previously mentioned reservoir in the headstockof the machine which drains back to the reservoir 52.

The construction just described is such thatv The passageway |40 is alsopro-,-

when the valve body 51 has been operated to eiect chuck closing orwork-gripping the recess |34 aligns with the ball detent |35 thusholding the valve body against return movement under the influence ofthe spring |3|. A portion of the fluid under pressure, which is suppliedthrough the passageway or port 62 by this position of the valve, nowpasses through the passageways |36 and |38 and through the conduit |39to the passage |40 in the valve casing, the rate of flow of the iiuidbeing regulated by the adjustment of the needle valve |31. Since thepassageway |40 is in communication with the cylinder |44 the piston |45is moved to the left, as viewed in Fig. 7, any fluid in advance of thepiston being exhausted through the port |48 and the pipe |21 to thelubrication reservoir in the ll'ieadstock I0.

Due to the restriction of the passageway |36 by the needle valve |31 acertain predetermined length of time is required before sufficient fluidhas entered the cylinder |44 to move the piston 45 to its extremeleft-hand position as viewed in Fig. 1. During this interval thepressure within the cylinder 16 of the mechanism 36 will have built upto a suflicient value to fully operate the collet chuck to itsWork-gripping position, the length of time required for the piston |45to move through the cylinder |44 being adjustable by the adjustment of aneedle valve |31. When the piston |45 has reached its extreme left-handposition, the pressure of the iiuid therein and in the passageway |40increases and this increased pressure acts upon the plunger |29 to movethe latter to the right, as viewed in Fig. '7 thereby assisting thespring |3| to return the valve body 51 to its neutral position since theforce thus exerted is suflicient to overcome the action of the springdetent |34.y

When the valve body 51 has thus returned to its neutral position thepassageway 1| is in communication with the passageway 10 so that fluidunder pressure is now applied through the pipes or conduits |21 and |49to the port |48 of the cylinder |44. This moves the piston |45 back toits position as shown in Fig. '1 preparing the mechanism for a newoperation. As mentioned before, .the pressuring iluid also flows throughthe pipe or conduit |21 into the lubrication reservoir of the headstockof the machine when the valve is in its neutral position. While thepiston |45 is moving back to its initial position the uid in advancethereof is exhausted through the passageway |40, recess |4| andpassageway |42, since the return of the valve to its neutral positionplaces the recess |4| in alignment with the passageway |40.

In order that the pressure employed in effecting work-gripping by thecollet chuck may be determined, so that the proper pressure may beemployed for the type of stock utilized, a pressure indicating means |50is provided. This pressure' indicator may be a conventional pressuregauge and is connected with the conduit 12 by a pipe or conduit |5| sothat the'uid pressure applied to the mechanism 36, in a direction tooperate the collet chuck to work-gripping position, will be indicated.During the actuation of the collet chuck to its work-gripping position,the uid pressure'required to move the tapered portion of the iingeractuating cone 28 beneath the finger rollers 29 is substantiallyproportionall to the gripping pressure exerted by the jaws of the colletchuck. 'Howeven when the rollers 29pass up on'the land of the fingerlpresflsure SI5 actuating cone 28 ,theu-id pressure in the-apparatusmomentarily drops and then is rapidly raised .to a highvalue when.thefpston',i3 reaches the 'end `of its. strokeand rthexbar;feeding.Ine'clfianisrnis actuated. Theselatter-men-y tioned pressuresaredisproportional to :thatof the workr'gripping'pressure Aexertedby/lfle-jaws *of the chuck. In vorder .toprevent .these lattermentionedpressures, vivllfich appear vin `the, viprnfi 'of a surgevor-fsurgesfof'fluid pressure in the pipes 'i2 and 15|, from registeringuponthe gauge |50 novel Adevice |52 is interposed 4heimweengtlfie pipe"or conduit andthe-pressurefgauge150. p l

"As shown most 'clearly'.in Figs.- '5 arid 5a lof lthe "drawings, thissurge. -prevention device |52 v'com'pri'sesfa bore vor cylinder 1153`Ain which is slidably positioned apiston o'r plunger liELt-he upper endof which is provided vwithan 4.extension 'oi reduced'diar'neterldesignated lea, `This 'piston "|54 .is normallyiieldfa'gain'stfthe-bottom of Athe here |53 by acum-pression'spring-:|55 and the bottom 'of the loo'r'e |53 communicates v with acentral passagewayfil'of reducedtdiarrieter with Yrespect to 'the 'bore|53, the pasvsfag'eilay |56 in.' turn 'communicating `with fthe pip'e5|. The piston vo'r plunger |54 'is fp'rovid'ed with 'la 'central bore,having `2.1.'clian1cterlarger than' that ef the passageway 1st, fendthis here inthe piston `is providedawithxa to'rtuous-path or fluid flowresistance fl51 of Y'suitable construction, fforveirample, like thatdisclosed-Fin myco- Ipending application VSerial 'No.636,089,^1ed 'onVDecejnl'jer 19, 1945, `'and "nowr'issued fas-Patent Nos 22505221. Theplunger or` piston is'. also 1pro- "v' edV 'with V"a l'recess 'or groove1454i). extending "around its periphery "andlintersectingthe lower `f "eprovided by the (editora 'ofthe fiuidriow resistor "on` flow 4'retarlr"created -in Etitle pi citi, Hence, the pressure lis frietinimeaiateiyiappued i' if feinte fthe spring ever, Iby "the n sed 'toaniair'iu'nt correspondand `Nil "has lin iris approximately "to theLvlower limit/of the operating 'r'anigle A"of collet-ichclrpressues'-th'e Spiston |54 will be unseated'agzaist tthe-faction'of the spring'|55 so that theiluidpressure is applied to the "gauge A4|513 throughthe? port "|59 "and bore |60. Fluid under :pressure Vv'also v'passesthrough the passageway "|587 in the-pistoh'if ythusV entering "the upperend of the bore/|53 j above the piston. This `e'nafele's'theiluidf'pr'escause the piston F554 tio-again"sawagamst the bottom Aof'the-hre The `'devit'z'e "is iso designed that this freseatingef- Itheypistesf'cmeurs when the 'huid-pressure in the pipes 4ia 'and 'rex m0-Eme'ntarily drops fiiiie 'to-the rollers 29 passing i'up f o'nt'o theland 'of :the iingeractuatingxcone '28.

Thefor'ce exetedwbyvfluid.trapped above the pist'on' 1| 5e, 'togetheri'with Vthe-force -of the `spring |55, is 'sumciently --great-tgo-prevent theunseating .1 oi- `^the.A piston 1| 54 when Y :themomentary surge of5pressure occurs as qthe pistonV I"I3A reeclnesy the'ndgof i its stroke 'and the 4har feeding mechanism is,I actuated ysincethis llatter pressure acts against the relatively srnallfarlea' of thelower ace of the ,pistoniS-fl corresponding to the area oi thepassageway |55 while l,the iiuidtrabled above the piston acts upon the.entire area of the upper vsurface oi the piston. gHence, surgerof tpressure isn-not indicated .on Athe indicator |59.

Yg The iiuid which4 is inrtheupper portion or" kthe bore 153, as aresultof the operation just 'dei scribed, gradually nds its wayhack1'i'.hrou'ghthe g flomretarder oruid-resistr |51 whenthe cohduit 'l2 isconnected with the e'iliaus't 'port Aor 'passage Si by the lreturn ofvthe manually 'operated yvalve to its neutral position.l I-'l'encetheiluid pressure abovethepiston |515 is 'dissipated "during the `machiningoperation Vand before' the next operation oi the vs :ollezt chucky Asothat the pressure yfor unseatingthe piston upon the next operation needonly -be great enough to over- -comev'the foroeg-oi the spring 155. Thedevice then acts as before, to {prei/ent .the undesirable `surge vorpressure pulse, whichis disproportional tothe gripping pressure oft-hechuck, from ybeing indica-tedqon the fgauge 165). The `i'low 'retarder|51 Voffers `s uihcient obstruction to vthe .passage of the liquid sothat Is11bstantial'ly none of the liquid ,l is forced' Supwardlytherethrough during -rthe rela-tively -short interval .during which thecollet-chuckis'beingactuat'ed A pressure relier", valve Il'n of,conventional construction is prefer-ably ,connectedbetween the conduits55 andft asia safety ieature to pre- :vent excessive VApressuresfrombeing developed --inthe system. As will-.be readily understood,

'any excessive pressure Which-is-developed within the system byoperationyof the pump A53 .-isrevlieved through this relief valveA ISI Atothereturn A'confini-U68.

, t-is #believed-that fthe V,Operation of the device will lnow `loeapparent-iremthe foregoing -description. However, itrnaybehrieflysummarized vas follows: o Let ity bejassLune'd-that a machiningoperation has Ajustjoeven completed-'uponayportion Iof thelength oftheparl s tocilif-Z :positioned intheapparatus.y The various parts-ofthe-ap paratus will then be in thepositions"illustrated in the drawingswith thecollet chuck22 in work- --grippingiposition, the nuts |20vonfthe -screw vH9 in engagement withthelug |fonlthe-uidactufatedmechanism -3,; and the ,rnanually operated control valve 53; ink itsnneutral A, position.` v Hence,

. 53 andl |669 'in thefysurge fprevention device .for

"actuated mechanismtetlie bores (ar-cylinders the `indicata-1i' glei),and. Ithe passageway |40 in i vthe valve casing-55 4arefincommunicationfwith the lreservoir #52 ythrough the recesses and, pas-ASaget/ars 65,' 56:6?,Mlfrandlmiof thefvalve-i-s operation' and) hencefluidxunderfpressure" will be 'supplied throughtherecess'ee'and;thepassageways"69 and-"fil of' the*valve-,W5iarid'lthrough the -fvalve 1casing 59.

The machining 'operationupon the bar f stock -fbeing completed and they:machined :portion severed therefrom;- the operator moves thevactuatingv handle .l2/i5v of .the valve-572iV in Y the-direction waySSAinto' alinment"withvthaportor,,passage- ,Way 6| and m40/Vins:thefpassasgwaysjsn,and' 'lo out of alignment with the ports orpassageways 62 and 1|, respectively. This movement'of the valve doesnot, however, interrupt the communication between the recess 65 and thepassageway 62, or the communication between the recess |4| and the.passageway |40, due to the relatively large sizes of these recesses.This actuation of the valve member therefore results in the supplying ofiiuid under pressure to the port 80 of cylinder 16, and to the ,ports 80and S2 of the cylinder or bore 83, while the port 11 of cylinder 16 andports 90 and 93 of cylinder 83 remain in communication with the iuidexhaust or return path to the reservoir 52. Hence, the piston 18 and thevalve member 84 are moved to their extreme right-hand positions asviewed in Figs. 2 and 6 of the drawings. This movement of the piston 18rocks the lever or yoke 32 in a counterclockwise direction, as viewed inFig. 2, thereby retracting the finger actuating cone 28 so that thenatural resiliency of the jaws of the collet chuck causes the said jawsto move to work releasing positions since the finger rollers 29 are nowfree to move inwardly.

When the piston 18 has completed its movement, thereby completelyreleasing the jaws of the collet chuck, the port 8| in the cylinder 16is uncovered so that uid under pressure now flows from the port 80through the space in the cylinder behind the piston 18, through the port8|, pipe |25 and port 9| to the space between the lands 88 and 81 of thevalve 84. It will be remembered that the valve 84 has now moved to itsextreme right-hand position and hence a lpathway for the fluid isprovided between the lands 88 and 81 of the valve 84 so that the fluidflows through the passageway 95 into the cylinder 98 at the right-handside thereof. This fluid entering the cylinder 98 then acts upon thepiston moving the latter to the left and correspondingly moving the barstock feeding chuck 20 because the clutch in the lower portion of thelatter mechanism operates to clutch the bar feeding chuck 20 with theportion ||0 of the piston rod 99 connected. with the piston |00. Sincethe jaws 45 of the bar feeding chuck 20 are gripping the bar stock 2|,the latter is thus fed through the hollow spindle of the machine tooland through the collet chuck 22 thereof.

The bar stock 2| is thus fed until its forward end abuts a xed stop, notshown, upon the machine tool. Just prior to this abutment,.how ever, thepiston |00 within `the cylinder 98 will have closed the port |0| exceptfor the restricted orifice pro-vided by the tapered opening or recess08, so that the iiuid between the piston and the plug 91 must nowexhaust to the passageway |02 through the said tapered opening |06. Thisretards the exhausting of the fluid in advance of the piston and acts asa dashpot or brake so that the bar stock engages the aforementionedfixed stop without exerting sufficient force thereon to cause recoil orundue stressing of the parts. The piston |00 moves substantially intoengagement with the plug 9i during each feeding stroke, the length ofthe stroke having been determined by the adjustment of the screws |29which regulate the distance which the piston |00 moves away from theplug 91 during the non-feeding or return stroke of the piston.

The release of the collet chuck and the feeding ofthe bar stock areeffected in the above described sequence in a relatively short intervalof time so that theoperator need not hold the handle |28 of the valve atits operated position.

The valve when released is lautomatically returned to its neutralposition by the action of the spring |32 acting upon the radialprojection |28 on the valve body 51 so that the several cylinders orbores of the actuating mechanism 38 are again vented or exhausted to thereservoir 52 as previously described.

The operator now moves the handle |26 in the reverse direction to thatin which he initially moved it so that the valve body 51 is now rotatedin a counterclockwise direction, as viewed in Figs. 2 and 7. Hence, thepassageway 84 is now in communication with the port or passageway 62,the recess 65 is in communication with the port or passageway 8|, andthe passageway 10` and recess ||l0 are, respectively, moved fromcommunication with the passageways 1| and |40. The operator may nowrelease the handle |26 since the recess |34 in the valve body is engagedby the ball detent |35 thus holding the valve in its oplerated position.Fluid under pressure is now supplied to the port 11 in cylinder 18, andto ports 90 and 93 of the cylinder or bore 83, the port 80 of cylinder18 'and ports 89 and 92 of cylinder 83 now being vented or exhaustedthrough the pipe |2| as previously described.

'Ihe fiuid entering the cylinder 16 through the port 11 moves the piston18 to its extreme left position, that is, to the position illustrated inFigs. 2 and 6, and the fluid entering the ports 90 and 93 of thecylinder or bore 83 move the valve 84 to its illustrated position. Thismovement of the piston 18 rocks the lever 32 in a clockwise direction,as viewed in Fig. 2, so that the nger actuating cone 28 rocks the ngers21 of the collet chuck mechanism in the direction which effects closingof the jaws of the collet chuck to workgripping position upon the barstock 2| which has just been fed.

When the piston 18 reaches the end of its stroke, and occupies theposition illustrated in the drawings, the port 8| is opened so thatfluid under pressure now passes therethrough, and through the pipe |25,entering the cylinder or bore 83 through the port 9| between the lands86 and 81 of the valve 84. valve are now so positioned that thepassageway 02 is uncovered and the passageway 95 is sealed from the port9|. The fluid under pressure therefore unseats the ball valve |04 andenters the cylinder through the port |03. causes the piston |00 to moveto the right,.as viewed in Figs. 2 and 6, it being remembered that theright-hand end of the cylinder 98 is now vented or exhausted through thepassageway 95 which communicates between the lands 81 and 88 with theport 92 and the pipes |24 and |2I. As the piston |00'moves to the rightits piston rod 99 moves to the right until the nuts |20 abut the lugprovided upon the housing 82 of the' fluid actuated mechanism 36, thesenuts being adjusted so that the distance which the pistonl |00 moves isequal to the desired predetermined length of bar stock which is to befed in the feeding operation. During this movement of the piston rod thebar stock feeding chuck 20' remains stationary since the jaws thereofare gripping the bar stock 2|, the portion l| l0 of the rod slippingthrough the lower portion of the frame 38 of this chuck as permitted bythe roller clutch carried thereby, see Fig. 4.

A portion of the iiuid under pressure which is applied through thepassageway |52 to the conf duit 12, for effecting the collet chuck andvbar feeding operations just described., is also applied These lands ofthe This through the passageways |3, |38, and pipe i3d to the passagewayIt@ in the body te of the valve.

the rate of application of fluid through this path being regulated bythe needle valve it?. This portion of the fluid enters the cylinderthrough the port Uit causing the piston M5 to move to the left, asviewed in Figs. 2 and 7, the fluid in advance of the pistni beingexhausted through the port Uit and pipes its and H21 to the lubricationreservoir, not shown, in the headstock of the machine. When the istonille reaches the end of its stroke, the pressure of the fluid in thepassageway ist increases until it, plus the force of the spring lill, issuiicient to overcome the force of the spring pressed. detent |35 sothat the plunger |29 is moved to the right, rocking the projection E28and the valve body .fil in a clockwise direction, thereby returning thevalve body 5l to its neutral position. The needle valve |31 is soadjusted that a predetermined time elapses from the time that the valve518 is operated, to eifect chucking of the bar stock, and the time whenthe pressure in the passageway It@ is sufficient to return the valve 58to its neutral position, the said predetermined time being suffin cientto insure that adequate fluid pressure will have developed. within thesystem to completely actuate the pistin it to its extreme left-hand position with consequent closing of the chuck, to work-gripping position.

The bar stock which has thus been fed and chucked may now be subjectedtc any desired machining operations and when these operations arecompleted, and the machined portion of the stock severed, the operationsabove described are repeated it being remembered that it is onlynecessary for the operator to sequentially,v move the handle |2 of thevalve 58 in two different directions to effect release of the colletchuck. from the bar stock, feeding of the bar stock, and gripping of thefed bar stock by the collet chuck.

Each time that the collet chuck is operated to work-gripping positionthe gripping pressure exerted thereby is indicated upon the indicator|553 which is connected, through the surge prevention device |52, withthe conduit l2 through which iiuid under pressure is applied foractuating the mechanism 36 in a manner to effect work-gripping by thechuck. The surge prevention device operates7 as previously described, toprevent erroneous indications upon the gauge 5i) due to the momentaryhigh pressure developed in the system when the rollers 2t of the nngersgli are upon the land portion of the cone, the piston 'FB has reachedthe end of its stroke, and the i feeding mechanism is actuated. l

After the bar feeding chuck. has advanced by repeated operations thereofto its extreme forward position, so that the bar feeding chuck housingis abutting the bracket member |151, the operator grasp the handle orlever i i5 and rock it so that the pin l i1 releases the roller ils ofthe clutch in the lower portion of the housing Se for the bar stockchuck 2G. He may then strip the bar stock chuck im rearwardly over thebar stock, to the right as viewed in 2, 3 and 4, the portion lil of thepiston rod 'S59 now passing freely through the housing 38. The lever i(E may then be returned to its initial position and the apparatus willoperate as described above. However, the return of the bar feeding chuckto the initial position, in the manner just mentioned, is not necessary.t will be remembered that the piston lill? and its rod 99 movelrearwardly of the machine, in preparation to feed a 20 new length. ofthe bar stock, while the chuck 22 is gripping the stock. Hence, if thehousing 3u of the bar feeding chuck is in engagement with the bracketmember lill when the latter is moved by the piston It@ and rod 89, thebracket member it? will carry the bar feeding chuck with it since thejaws of the latter will slip or strip along the bar stock, the springsit in the bar chuck yielding slightly to permit this action. When themechanismy is operated in a bar feeding direction, however, the chuck 2Eis in released position and hence the jaws ile of the bar chuck grip thebar stock with sufficient force to feed the bar stock as beforedescribed. Hence, the bar stock may be fed by the mechanism of thisinvention until the rear end thereof is closely adjacent the rear end ofthe hollow spindle When substantially all of the bar stock has been fed,the handle H6 is then actuated, as described above to release the rollerclutch and the bar feeding chuck is moved rearwardly of the machinecarrying with it the bar stock supporting tube Hi. A new piece of barstock is then inserted in the tube I9, which may be moved out ofalignment with the spindle for this purpose due to the pivotal mountingof `the sleeve lla and the usual relatively wide upper surface 0f thebracket I4. After the new piece of bar stock is in the tube I9 thelatter is returned to alignment with the bar feeding chuck 2u and thespindle 23. The forward end of the new piece of bar stock is theninserted through the jaws i5 of the feeding chuck 20 and the handle |16is returned to the position for again rendering the roller clutchoperative. The mechanism is then actuated as before to feed the barstock. If desired, the forward end of the new piece of bar stock may 4becaused to abut the rear end of the previously employed piece of barstock so that the latter is fed, by each actuation of the feedingmechanism, until it has completely passed through the work-holding chuck22.

Numerous modifications and adaptations of the apparatus hereinillustrated and described will readily occur to those skilled in the artand. hence, the invention is not to be considered as limited to theexact details of construction and arrangement of parts hereinillustrated and described, but only as required by the spirit .and scopeof the appended claims.

Having thus described my invention, I claim.:

1. In a machine tool of the character described for operating upon barstock and having a wor-ksholding `chuck adapted to grip a portion of the.bar stock operated upon, the combination of the first cylinder havingports adjacent either end and single port intermediate the ends thereof,a piston in said cylinder, operative connections between said piston andthe said work-'holding chuck to actuate the latter by movement of thefor-mer, a second cylinder having ports adjacent either end thereof, apiston in said second cylinder, a ,bar feeding chuck, operativeconnections between said second piston and said bar feeding chuck tobodily move the latter in a .direction effecting feeding of .bar stockthrough the work-holding chuck when the second piston moves in onedirection and to cause relative movement between said .bar feeding chuckand said second piston when the latter moves in the opposite direction,a uid actuated valve including a movable member having spaced landsadapted to selectively connect said single port of the rst cylinder toeither of .the ports of the second cylinder and the other of said portsof said second cylinder to a drain,

-21 means for supplying a fluid under pressure, a multiple passagewayValve for selectively connecting said source of fluid under pressure toeither end port of said first -cylinder and to ports adjacent either endof the movable member of said liuid actuated valve to act upon lands ofthe latter so that the application of fluid under pressure to said first-cylinder for operation of the .work-holding chuck also actuates saidfluid operated valve to a position for application of fluid underpressure from the first cylinder through said intermediate port to saidseco-nd cylinder after the said first piston has substantially com-.pleted its stroke, whereby the bar stock is fed only after thework-holding vchuck has been completely released and the connections tothe bar feeding chuck are conditioned for bar .feeding operation onlyaf-ter the work-holding chuck has Ibeen completely actuated towork-gripping position.

2. The combination as defined in claim 1 and further comprising means toretain said multiple .passageway valve in that operated position thereofwhich effects actuation of the work-holding .chuck to gripping position,fluid pressure actuated means for automatically returning said multiplepassageway valve to neutral -position after operation thereof, and meansto apply fluid `under pressure to the last-mentioned means at a pre-.determined rate to assist the latter to overcome said retaining means apredetermined time after .the multiple passageway valve is actuated to-work-gripping position.

3. The combination as defined in claim 2 and in which means are providedto adjust the length .of time said valve is held in its said operatedposition.

4. The combination as defined in claim 1 .wherein the said secondcylinder has a tapered opening in the side Wall adjacent an end thereofproviding one of the ports for said second cylinder, the said openingbeing progressively covered by the said second piston thereby brakingthe movement of the piston and of the bar stock.

5. The combination as defined in claim l and in which the said operativeconnections between said second piston and said bar feeding chuck`comprise a one-way clutch which couples the saidbar feeding chuck withsaid second pis-ton for movement together when the said second piston ismoved in a bar feeding direction and permits said bar feeding chuck toremain stationary when said second piston is moved in the oppositedirection.

6. In a machine tool of the character described for operating upon barstock and having a workholding chuck adapted to grip a portion of thebar stock operated upon, the combination of a first cylinder having aport adjacent each end and a port intermediate its ends, a piston insaid` cylinder having a length sufficient to seal said intermediate portat all times except when said vpiston is at either extreme position inthe cylinder, operative connections between said piston andthework-holding chuck to actuate the latter .by movement of the former, asecond cylinder, a .piston in said second cylinder, a bar feeding chuck,Operative connections between said second piston vand said bar feedingchuck such that -movement of said second piston in one direction movessaid bar feeding chuck in a direction to cause feeding of the bar stockthrough the work- Iholding chuck and movement of said second .piston inthe other direction causes relative movement between the latter and saidbar feeding chuck, the said second cylinder having ports adjacent theends thereof, a hydraulically operated valve having a plurality ofports, a mul-tiple .passageway main valve, a source of liquid under.pressure -connected with said main valve, hyldraulic connections fromsaid main valve to the .end ports of said first cylinder and to certainof the ports of said hydraulically actuated Valve, vhydraulicconnections between .the intermediate port of said first cylinder 'andone of the ports of said hydraulically actuated valve and hydraulicconnections between the remaining ports of said hydraulically actuatedvalve and the ports of said second cylinder such that the saidhydraulically actuated valve selectively establishes communicationbetween said intermediate port .of said first cylinder and one or theother of the .ports on opposite sides of the piston in said sec- .ondcylinder, whereby operation of the said main valve to onepositionsupplies liquid under pressure to the hydraulically actuated valve andto .the first cylinder actuating the former and causing the piston inthe latter to actuate the workholding chuck to work releasing positionand to uncover said intermediate port so that the liquid under pressurepasses therethrough and through said hydraulically actuated valve toenter said second cylinder through one of the ports therein causing thepiston in the said second cylinder to move said bar feeding chuck in thebar feed- :ing direction, and operation of the main valve in .theopposite direction supplies liquid under pressure to said hydraulicallyactuated valve and to said first cylinder to actuate the hydraulically.actuated valve and first vpiston in the opposite direction therebyactuating the work-holding lchuck to work gripping position andthereafter supplying liquid under pressure to said second .cylinder toreturn the piston therein to its initial position so that the apparatusis prepared to feed a new length of bar stock upon the next actuation ofsaid main valve in the proper direction.

7. The combination as defined in claim 6 and further comprising meansapplying a resilient restoring force to said main valve when it isdisplaced from its neutral position to effect auto- ,matic returnthereto.

8. T-he combination as defined in claim 6 and lfurther comprising meansapplying a resilient restoring force to said main valve vwhen it isdisplaced from its neutral position, means to hold said main valve inthe operated position thereof wherein it supplies fluid forwork-gripping by the work-holding chuck, and fluid actuated meansoperating upon said main valve to restore it to its neutral position apredetermined interval of time after it has been actuated to said oper-.ated position.

9. rlhe combination as defined in claim 6 and vfurther comprising Ameansto indicate those hy- :draulic pressures applied to the said rstcylinder which are proportional to the pressure exerted by thework-holding chuck upon the bar stock, and means to prevent surges ofhydraulic pressures which are disproportional to the work-holdingpressures from being communicated to said indicating means.

10. The combination as defined in claim 6 and in which the .saidoperative connections between the rst piston and the work-holding chuckinclude a floating lever pivotally connected to said first piston and toa movable part of said workholding chuck, and a pair of links pivoted ona stationary part of the machine tool and to the said floating lever inspaced relationship along 23 the'latter in a manner such thatsubstantially the entire force exerted by the said first piston iseffective to operate said Work-holding chuck.

11. In a machine tool of the character described for operating upon barstock and having a work-holding chuck adapted to grip a portion -of thebar stock operated upon, the combination .of a bar feeding chuck, afluid actuated piston operatively connected to said Work-holding chuckto operate the latter, a second fluid actuated .piston operativelyconnected to said bar feeding `chuck to bodily move the latter, fluidactuated valve means between said first and second pistons operative toselectively control the supplying of `fluid under pressure to eitherside of said second piston, valve means for selectively applying fluid'under pressure to either side of the first-mentioned pis-ton and tosaid fluid actuated valve means for effecting operation of the latterand of said Work-holding chuck, and fluid passageways uncovered bymovement of the rstmentioned piston at either extreme of its extent ofmovement for conducting a portion of the fluid supplied thereto throughthe said fluid actuated valve means to the said second piston at -thatside thereof as determined by the actuated Iposition of the fluidactuated valve means, wherefby the bar stock feeding chuck is moved onlyafter the work-holding chuck has been fully operated.

12. The combination as defined in claim 11 .wherein the operativeconnections between the second piston and said bar feeding chuck includemeans providing a positive connection of the second piston to thefeeding chuck when the said second piston moves in a direction toproduce .feeding of, the bar stock and permits` relative movementbetween the bar feeding chuck vand .the second piston when the lattermoves in the opposite direction, and means for determining the length ofbar stock fed comprising a sta .tionary lug, a lug connected to :aportion of said operative connections between said bar feeding chuck andsaid second piston, an elongated threaded member carried by one of saidlugs and movable through an Iopening in lthe other, and nut-likeabutment means adjustable on the portion on said elongated threadedmember extend- `ing beyond the sai-d other lug and adapted to engage thelatter for limiting the amount of separation between said lugs therebylimiting the movement of said piston in the non-bar feeding direction.

FAY IVI. TOMLINSON.

References Cited in the le of this patent UNITED STATES PATENTS NumberName Date 1,604,115 Drissner Oct. 26, 1926 1,844,107 Sheperdson Feb. 9,1932 2,019,155 Ruppel Oct. 29, 1935 2,047,832 Mor-ton July 14, 19362,067,064 Platz Jan. 5, 1937 2,078,698 Svenson Apr. 27, 1937 2,116,376Anderson May 3, 1938 2,308,348 Ballash Jan. 12, 1943 2,339,712 MarietteJan. 18, 1944 2,366,908 Jenkins Jan. 9, 1945 2,369,466 Kylin et al Feb.13, 1945 2,372,408 Trich Mar, 27, 1945 2,451,210 Gamble Oct. 12, 1948

